The major goal of the research effort was to precisely locate the von Hippel-Lindau disease (VHL) gene. Multipoint linkage analysis was performed with a panel of 25 families with von Hippel-Lindau disease. The results of this analysis indicate that the most likely location for the von Hippel-Lindau disease gene is on chromosome 3 in the interval between RAF1 and D3S18. A probe was identified that is inherited with the von Hippel-Lindau disease gene in 96% of genetic events (meiosis). Because probe CRI-L162 (D3S18) is consistently inherited with the disease gene it should prove to be useful in presymptomatic diagnosis of von Hippel-Lindau disease. A prospective trial to test this hypothesis is in progress. Asymptomatic, at-risk individuals were examined for evidence of von Hippel-Lindau disease. Twenty-two asymptomatic individuals were found to have the disease. These individuals were treated at the National Cancer Institute or were referred for treatment by physicians in their communities.